Efficacy of cutting balloon angioplasty for lesions at the ostium of the coronary arteries

We evaluated 37 patients (39 lesions, 11 women/26 men, median age of 66 years old) with coronary ostial lesions who underwent cutting balloon angioplasty (CB). Seventy-four patients (78 lesions, 18 women/56 men, median age of 65 years old) who had undergone plain old balloon angioplasty (POBA) for coronary ostial lesions were also enrolled as the control group. At clinical diagnosis, unstable angina was seen in 8.1% of the CB group and in 9.5% of the POBA group. Post myocardial infarction silent ischemia was seen in 28.3% of the POBA group and 32.4% of the CB group. The success rate was 94.8% in the CB group and 84.6% in the POBA group. The frequency of intimal dissection was not significantly different between the two groups. However, all cases of intimal dissection in the CB group were mild (either type A or B), whereas the POBA group included many cases of severe intimal dissection (types B through F). No cardiac event was observed in the CB group. However, in the POBA group, cardiac death occurred in 1.4% and emergency bypass surgery occurred in 0.7% of the patients. Calculating the restenosis rate based on the cumulative percent diameter stenosis curve resulted in 43% for the CB group and 53% of the POBA group. We concluded that the cutting balloon was useful for ostial lesions as compared to plain old balloon angioplasty.

Effects of calcium supplementation on calcium homeostasis and bone turnover in lactating women

Lactation is a time of calcium flux, because women secrete approximately 210 mg calcium/day in breast milk, and they experience a transient bone loss. The objectives of this study were to determine the effect of calcium supplementation on adaptive responses in calcium homeostasis during lactation and after weaning. Two cohorts of women participated in a 6-month randomized calcium supplementation trial. Lactation cohort women (97 lactating, 99 nonlactating) were studied during the first 6 months post partum, and weaning cohort women (95 lactating, 92 nonlactating) were studied during the second 6 months post partum. Lactating women in the weaning cohort weaned approximately 1.5 months after enrollment. PTH was 18-30% lower in lactating than in nonlactating women (P < 0.01). Serum 1,25-dihydroxyvitamin D was 11-16% higher in lactating than in nonlactating women and remained elevated for approximately 1.5 months after weaning (P = 0.06). Calcium supplementation decreased serum PTH and 1,25-dihydroxyvitamin D in lactating and nonlactating women similarly. At 6 months, the calciuric response to calcium supplementation was less in lactating (compared with nonlactating) women (P = 0.06). Biomarkers of bone turnover were higher in lactating than in nonlactating women during lactation and after weaning but were not effected by calcium supplementation. Calcium supplementation has little effect on lactation-induced changes in the calcium economy.

Localization of the intracellular activity domain of Pasteurella multocida toxin to the N terminus

We have shown that Pasteurella multocida toxin (PMT) directly causes transient activation of Gqalpha protein that is coupled to phosphatidylinositol-specific phospholipase Cbeta1 in Xenopus oocytes (B. A. Wilson, X. Zhu, M. Ho, and L. Lu, J. Biol. Chem. 272:1268-1275, 1997). We found that antibodies directed against an N-terminal peptide of PMT inhibited the toxin-induced response in Xenopus oocytes, but antibodies against a C-terminal peptide did not. To test whether the intracellular activity domain of PMT is localized to the N terminus, we conducted a deletion mutational analysis of the PMT protein, using the Xenopus oocyte system as a means of screening for toxin activity. Using PCR and conventional cloning techniques, we cloned from a toxinogenic strain of P. multocida the entire toxA gene, encoding the 1,285-amino-acid PMT protein, and expressed the recombinant toxin as a His-tagged fusion protein in Escherichia coli. We subsequently generated a series of N-terminal and C-terminal deletion mutants and expressed the His-tagged PMT fragments in E. coli. These proteins were screened for cytotoxic activity on cultured Vero cells and for intracellular activity in the Xenopus oocyte system. Only the full-length protein without the His tag exhibited activity on Vero cells. The full-length PMT and N-terminal fragments containing the first 500 residues elicited responses in oocytes, but the C-terminal 780 amino acid fragment did not. Our results confirm that the intracellular activity domain of PMT is localized to the N-terminal 500 amino acids of the protein and that the C terminus is required for entry into cells.

Functional effects of the muscarinic receptor agonist, xanomeline, at 5-HT1 and 5-HT2 receptors

Xanomeline [3(3-hexyloxy-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-me thylpyridine] has been reported to act as a functionally selective muscarinic partial agonist with potential use in the treatment of Alzheimer's disease. This study examined the functional activity of xanomeline at 5-HT1 and 5-HT2 receptors in native tissue and/or human cloned receptors. Xanomeline had affinity for muscarinic receptors in rat cortical membranes where the ratio of the displacement affinity of [3H]-Quinuclidinyl benzilate vs that of [3H]-Oxotremorine-M was 16, indicative of partial agonist activity. Radioligand binding studies on human cloned receptors confirmed that xanomeline had substantial affinity for M1, M2, M3, M4, M5 receptors and also for 5-HT1 and 5-HT2 receptor subtypes. Carbachol and xanomeline stimulated basal [35S]-GTPgammaS binding in rat cortical membranes with micromolar affinity. The response to carbachol was attenuated by himbacine and pirenzepine with pA2 of 8.2, 6.9 respectively consistent with the response being mediated, predominantly, via M2 and M4 receptors. Xanomeline-induced stimulation of [35S]-GTPgammaS binding was inhibited by himbacine with an apparent pKb of 6.3, was not attenuated by pirenzepine up to 3 microM and was inhibited by the selective 5-HT1A antagonist WAY100635 with an apparent pKb of 9.4. These data suggest the agonist effect of xanomeline in this tissue is, in part, via 5-HT1A receptors. Similar studies on human cloned receptors confirmed that xanomeline is an agonist at human cloned 5-HT1A and 5-HT1B receptors. In studies using the fluorescent cytoplasmic Ca2+ indicator FLUO-3AM, xanomeline induced an increase in cytoplasmic Ca2+ concentration in SH-SY5Y cells expressing recombinant human 5-HT2C receptors. Atropine antagonized this response, consistent with mediation via endogenously-expressed muscarinic receptors. In the presence of atropine, xanomeline antagonized 5-HT-induced cytoplasmic changes in Ca2+ concentration in cells expressing h5-HT2A, h5-HT2B and h5-HT2c receptors with potencies similar to its affinity at these receptors. These studies indicate that xanomeline is a potent agonist at 5-HT1A and 5-HT1B receptors and an antagonist at 5-HT2 receptor subtypes.

Raynaud's phenomenon: state of the art 1998

Raynaud's Phenomenon (RP) is a relatively common problem which may be troublesome and difficult to treat in a minority of patients. The state of the art in 1998 focusses on three key areas: the clinical spectrum of RP; its progression and prognosis; and its treatment. RP is a systemic disease, with a multifactorial aetiology and vasospasm affects not just the digits and skin but also major organs including the heart, lungs and kidneys. It is important to distinguish primary from secondary RP. RP may predate an associated connective tissue disease by many years and markers for this include severe RP symptoms with trophic skin changes, serological abnormalities and abnormal nailfold capillaries. Repeated attacks of vasospasm may cause ischaemic reperfusion injury to the endothelium, resulting in a vicious and self propagating cycle of cause and effect. Nifedipine remains the "gold standard" of treatment but a number of new and promising drugs, eg relaxin, are currently under investigation. "Vasodilator-plus" drugs, with the ability to also modulate some of the haemorrheological abnormalities in RP, are the drugs that are going to have a major clinical impact on the disease and hold promise for the future.

Outcome after treatment of high-risk papillary and non-Hürthle-cell follicular thyroid carcinoma

BACKGROUND

Treatment of differentiated thyroid cancer has been studied for many years, but the benefits of extensive initial thyroid surgery and the addition of radioiodine therapy or external radiation therapy remain controversial.

OBJECTIVE

To determine the relations among extent of surgery, radioiodine therapy, and external radiation therapy in the treatment of high-risk papillary and non-Hürthle-cell follicular thyroid carcinoma.

DESIGN

Analysis of data from a multicenter study.

SETTING

14 institutions in the United States and Canada participating in the National Thyroid Cancer Treatment Cooperative Study Registry.

PATIENT

385 patients with high-risk thyroid cancer (303 with papillary carcinoma and 82 with follicular carcinoma).

MEASUREMENTS

Death, disease progression, and disease-free survival.

RESULTS

Total or near-total thyroidectomy was done in 85.3% of patients with papillary carcinoma and 71.3% of patients with follicular cancer. Overall surgical complication rate was 14.3%. Total or near-total thyroidectomy improved overall survival (risk ratio [RR], 0.37 [95% CI, 0.18 to 0.75]) but not cancer-specific mortality, progression, or disease-free survival in patients with papillary cancer. No effect of extent of surgery was seen in patients with follicular thyroid cancer. Postoperative iodine-131 was given to 85.4% of patients with papillary cancer and 79.3% of patients with follicular cancer. In patients with papillary cancer, radioiodine therapy was associated with improvement in cancer-specific mortality (RR, 0.30 [CI, 0.09 to 0.93 by multivariate analysis only]) and progression (RR, 0.30 [CI, 0.13 to 0.72]). When tall-cell variants were excluded, the effect on outcome was not significant. After radioiodine therapy, patients with follicular thyroid cancer had improvement in overall mortality (RR, 0.17 [CI, 0.06 to 0.47]), cancer-specific mortality (RR, 0.12 [CI, 0.04 to 0.42]), progression (RR, 0.21 [CI, 0.08 to 0.56]), and disease-free survival (RR, 0.29 [CI, 0.08 to 1.01]). External radiation therapy to the neck was given to 18.5% of patients and was not associated with improved survival, lack of progression, or disease-free survival.

CONCLUSIONS

This study supports improvement in overall and cancer-specific mortality among patients with papillary and follicular thyroid cancer after postoperative iodine-131 therapy. Radioiodine therapy was also associated with improvement in progression in patients with papillary cancer and improvement in progression and disease-free survival in patients with follicular carcinoma.

Severe classical congenital muscular dystrophy and merosin expression

It has been suggested that patients with autosomal recessive merosin deficient congenital muscular dystrophy (CMD), as opposed to the merosin positive cases form a homogeneous subgroup of a clinically more severe form of CMD. We examined merosin expression in muscle biopsies from five children with the severe classical form of CMD. Merosin deficiency was found only in 1 patient, a 6-year-old female, with abnormal brain myelination. However, her initial biopsy did not reveal the classical picture of dystrophy. The four merosin positive cases exhibited severe muscle weakness but their brain imagings were normal. There were no familial cases, except for the mother of 1 patient who had a milder form of the disease, suggesting an autosomal dominant mode of inheritance. In contrast to previous reports, the merosin deficient CMD cases were rare in our group. Furthermore, merosin positive cases were also associated with severe phenotype suggesting that a severe phenotype is not exclusive to merosin deficient cases. Finally, the absence of merosin in a neonate with hypotonia and weakness can be helpful in making a definitive diagnosis of CMD, even though the dystrophic process may not be evident yet and histology may be non-specific.

Thyrotropin suppression and disease progression in patients with differentiated thyroid cancer: results from the National Thyroid Cancer Treatment Cooperative Registry

The ideal therapy for differentiated thyroid cancer is uncertain. Although thyroid hormone treatment is pivotal, the degree of thyrotropin (TSH) suppression that is required to prevent recurrences has not been studied in detail. We have examined the relation of TSH suppression to baseline disease characteristics and to the likelihood of disease progression in a cohort of thyroid cancer patients who have been followed in a multicenter thyroid cancer registry that was established in 1986. The present study describes 617 patients with papillary and 66 patients with follicular thyroid cancer followed annually for a median of 4.5 years (range 1-8.6 years). Cancer staging was assessed using a staging scheme developed and validated by the registry. Cancer status was defined as no residual disease; progressive disease at any follow-up time; or death from thyroid cancer. A mean TSH score was calculated for each patient by averaging all available TSH determinations, where 1 = undetectable TSH; 2 = subnormal TSH; 3 = normal TSH; and 4 = elevated TSH. Patients were also grouped by their TSH scores: group 1: mean TSH score 1.0-1.99; group 2: mean TSH score 2.0-2.99; group 3: mean TSH score 3.0-4.0. The degree of TSH suppression did not differ between papillary and follicular thyroid cancer patients. However, TSH suppression was greater in papillary cancer patients who were initially classified as being at higher risk for recurrence. This was not the case for follicular cancer patients, where TSH suppression was similar for all patients. For all stages of papillary cancer, a Cox proportional hazards model showed that disease stage, patient age, and radioiodine therapy all predicted disease progression, but TSH score category did not. However, TSH score category was an independent predictor of disease progression in high risk patients (p = 0.03), but was no longer significant when radioiodine therapy was included in the model (p = 0.09). There were too few patients with follicular cancer for multivariate analysis. These data suggest that physicians use greater degrees of TSH suppression in higher risk papillary cancer patients. Our data do not support the concept that greater degrees of TSH suppression are required to prevent disease progression in low-risk patients, but this possibility remains in high-risk patients. Additional studies with more patients and longer follow-up may provide the answer to this important question.

SB-224289--a novel selective (human) 5-HT1B receptor antagonist with negative intrinsic activity

1. Human 5-HT1B (h5-HT1B) and human 5-HT1D (h5-HT1D) receptors show remarkably similar pharmacology with few compounds discriminating the receptors. We report here on a novel compound, SB-224289 (1'-Methyl-5-[[2'-methyl-4'-(5-methyl- 1,2,4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydro spiro [furo [2,3-f]indole-3,4'-piperidine] oxalate), which has high affinity for h5-HT1B receptors (pK1=8.16+/-0.06) and displays over 75 fold selectivity for the h5-HT1B receptor over all other 5-HT receptors including the h5-HT1D receptor and all other receptors tested thus far. 2. Functional activity of SB-224289 was measured in a [15S]GTPgammaS binding assay on recombinant h5-HT1B and h5-HT1D receptors expressed in Chinese Hamster Ovary (CHO) cells. SB-224289 displayed negative intrinsic activity at both receptors with higher potency at h5-HT1B receptors. SB-224289 caused a rightward shift of agonist concentration response curves consistent with competitive antagonism and generated affinities comparable with those obtained from competition radioligand receptor binding studies. 3. SB-224289 potentiated [3H]5-HT release from electrically stimulated guinea-pig cerebral cortical slices to the same extent as as the non-selective 5-HT1 antagonist methiothepin. SB-224289 also fully reversed the inhibitory effect of exogenously superfused 5-HT on electrically stimulated release. 4. Using SB-224289 as a tool compound, we confirm that in guinea-pig cerebral cortex the terminal 5-HT autoreceptor is of the 5-HT1B subtype.

Prospective multicenter study of thyroiscarcinoma treatment: initial analysis of staging and outcome. National Thyroid Cancer Treatment Cooperative Study Registry Group

BACKGROUND

A novel prognostic staging classification encompassing all forms of thyroid carcinoma was created for the National Thyroid Cancer Treatment Cooperative Study (NTCTCS) Registry, with the goal of prospective validation and comparison with other available staging classifications.

METHODS

Patient information was recorded prospectively from 14 institutions. Clinicopathologic staging was based on patient age at diagnosis, tumor histology, tumor size, intrathyroidal multifocality, extraglandular invasion, metastases, and tumor differentiation.

RESULTS

Between 1987 and 1995, 1607 patients were registered. Approximately 43% of patients were classified as NTCTCS Stage I, 24% Stage II, 24% Stage III, and 9% Stage IV. Patients with follicular carcinoma were more likely to have "high risk" Stage III or IV disease than those with papillary carcinoma. Of 1562 patients for whom censored follow-up was available (median follow-up, 40 months), 78 died of thyroid carcinoma or complications of its treatment. Five-year product-limit patient disease specific survival was 99.8% for Stage I, 100% for Stage II, 91.9% for Stage III, and 48.9% for Stage IV (P < 0.0001). The frequency of remaining disease free also declined significantly with increasing stage (94.3% for Stage I, 93.1%for Stage II, 77.8% for Stage III, and 24.6% for Stage IV). The same patients also were staged applying six previously published classifications as appropriate for their tumor type. The predictive value of the NTCTCS Registry staging classification consistently was among the highest for disease specific mortality and for remaining disease free, regardless of the tumor type.

CONCLUSIONS

The NTCTCS Registry staging classification provides a prospectively validated scheme for predicting short term prognosis for patients with thyroid carcinoma.

Endogenous interleukin-10 modulates proinflammatory response in Plasmodium falciparum malaria

Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 are implicated in the pathogenesis of severe Plasmodium falciparum malaria. In this study, the effect of IL-10 on their production by peripheral blood mononuclear cells (PBMC) from acutely infected patients was examined. Exogenous IL-10 inhibited malarial antigen-induced cytokine production by reducing mRNA accumulation. Maximal inhibition occurred when IL-10 was added in the first 2 h of stimulation. Conversely, the addition of anti-IL-10 markedly enhanced TNF-alpha, IL-1beta, and IL-6 production. The effect was significantly greater on PBMC from patients with uncomplicated infection than PBMC from patients with severe disease. Kinetics studies showed that TNF-alpha, IL-6, and IL-1beta were produced within 2-4 h of stimulation, while IL-10 was first detectable after 8 h. These findings suggest that IL-10 counter-regulates the proinflammatory response to P. falciparum. Severe falciparum malaria may be associated with an inadequate negative feedback response by IL-10.

Characterization of Plasmodium falciparum-infected erythrocyte and P-selectin interaction under flow conditions

Plasmodium falciparum-infected erythrocytes (IRBC) roll on the adhesion molecule P-selectin in vitro under flow conditions that approximate the shear stress in capillary and postcapillary venules in which cytoadherence occurs in vivo. The pathological significance of this adhesive interaction is currently unknown. In this study, we further investigated the molecular interactions between IRBC and P-selectin by using a laminar flow system that allowed for the direct visualization of IRBC-substratum interactions. The results showed that the IRBC-P-selectin interaction was Ca2+-dependent and involved the lectin domain of P-selectin and a sialic acid residue on IRBC. The sialylated P-selectin ligand was trypsin-sensitive, which suggests that it could be part of the parasite antigen PfEMP1 that interacts with CD36 and intercellular adhesion molecule-1 (ICAM-1), but different from a trypsin-resistant IRBC ligand that adheres selectively to chondroitin sulfate A. Studies on the rolling and adhesion of IRBC on activated platelets that express both CD36 and P-selectin showed that inhibition of rolling on P-selectin reduced the adhesion of some clinical parasite isolates to CD36, whereas other parasite isolates appeared to interact directly with CD36. Thus, cytoadherence under physiological flow conditions may be mediated by multiple IRBC ligands that interact with different adhesion molecules in a cooperative fashion. These findings underscore the complexity of the interactions betweeen IRBC and vascular endothelium.

Axonal injury and the neuropathology of shaken baby syndrome

We examined an autopsy series of 14 children with shaken baby syndrome (SBS) who lacked skull fracture. Evidence of axonal injury was sought using immunohistochemical stains for neurofilament, 68-kDa neurofilament and beta-amyloid precursor protein (betaAPP). BetaAPP-positive axons were present in the cerebral white matter of all cases of SBS but were also present in 6 of 7 children dying of non-traumatic hypoxic ischemic encephalopathy (HIE). Swollen axons were present in 11 of 14 cases of SBS and in 6 of 7 cases of HIE. BetaAPP-positive axons were present in both groups in the midbrain and medulla. The cervical spinal cord in SBS contained betaAPP-positive axons in 7 of 11 cases; 5 of 7 contained swollen axons within the white matter tracts; in 2 immunoreactivity was localized to spinal nerve roots; in all 7 there was a predilection for staining at the glial head of the nerve root. Among cases of HIE, none showed abnormal axons or betaAPP-positive reactivity in the cervical cord white matter. We conclude that cerebral axonal injury is common in SBS, and may be due in part to hypoxic/ischemic injury. Cervical cord injury is also common, and cannot be attributed to HIE. These findings corroborate suggestions that flexion-extension injury about the cervical spinal column may be important in the pathogenesis of SBS.

Current outlook of infectious diseases in Taiwan

The "emerging" infectious diseases have received global attention. Taiwan is a country which is going through the process of becoming "developed" from being "developing". If we compare five leading causes of death in 1952 and in 1993, three were infectious diseases in 1952 and there was none in 1993. And yet today, infectious diseases remain a major problem in this country as well in every country in the world, whether developing or developed. Some of the problems Taiwan faces are old problems with old faces. They have never been adequately solved because the societal and environmental sanitary infrastructure does not ensure proper sewage disposal, safe potable water and freedom from dangerous vectors. Examples are the diarrheal diseases, parasitic diseases, scrub typhus and Japanese encephalitis. Some of the Taiwan's problems are caused by old agents which present a new face. Mortality from tuberculosis took a dramatic and gratifying plunge in the last fifty years. Yet tuberculosis is ever present and a constant public health threat. Dengue has become a problem again because of a world breakdown in the control of the mosquito, Aedes egypti, and it is partly contributed to by increased urbanization and world travel. The problem of antibiotic resistant bacteria causing hospital acquired and community acquired infections is probably the most serious "new" problem. The most important cause is excessive and indiscriminate use of antibiotics in the community and in hospitals. We propose the establishment of "Bacterial Infections Reference Laboratory" at the National Health Research Institutes to be a national facility to study the epidemiology and control of antibiotic resistance. All infectious diseases require a rigorous system of surveillance, and precise etiological diagnosis before they can be treated or prevented. This should be kept clearly in mind when one considers the changing role of the infectious disease physician in Taiwan in the face of unsolved disease problems and a new health care system. There is inadequate attention to precise microbiological definition of most infectious diseases in Taiwan. The community of infectious disease specialists may well redirect its attention to improving the competence and utilization of microbiological laboratory diagnosis.

Intramuscular ketamine for pediatric sedation in the emergency department: safety profile in 1,022 cases

STUDY OBJECTIVE

To determine the safety of intramuscular ketamine when administered by emergency physicians for pediatric procedures in accordance with a defined protocol.

METHODS

We assembled a consecutive case series of children aged 15 years or younger who were given ketamine in the emergency departments of a university medical center and an affiliated county hospital over a 9-year period. A protocol for ketamine use (4 mg/kg, intramuscularly) was followed. Treating physicians were instructed to complete data forms recording complications and adequacy of sedation concurrent with patient care. Subsequent chart review was used to determine indications, adjunctive drugs, time to discharge, and adverse reactions for all patients.

RESULTS

Intramuscular ketamine was administered 1,022 times, mainly for laceration repair and fracture reduction. Physicians completed data forms for 431 of treated children (42%). Transient airway complications occurred in 1.4%: airway malalignment (n = 7), laryngospasm (n = 4), apnea (n = 2), and respiratory depression (n = 1). All were quickly identified and treated without intubation or sequelae. Emesis occurred in 6.7%, without evidence of aspiration. Mild recovery agitation occurred in 17.6%, moderate to severe agitation in 1.6%. No child required hospitalization for complications caused by ketamine. Ketamine produced acceptable sedation in 98% of patients. The median time from injection to emergency department discharge was 110 minutes for children given a single dose of ketamine.

CONCLUSION

Intramuscular ketamine may be administered safely by emergency physicians to facilitate pediatric procedures in accordance with a defined protocol and with appropriate monitoring. Ketamine is highly effective, has a wide margin of safety, does not require intravenous access, and uniquely preserves protective airway reflexes.

Dietary supplementation with omega 3 and omega 6 fatty acids reduces induced white blood cell aggregation in healthy volunteers

Twenty healthy, non-smoking subjects were enrolled into a study to look at the effects of 3 months' dietary supplementation with long chain polyunsaturated essential fatty acids (EFAs) on white blood cell (WBC) aggregation. Ten subjects received 3 months' supplementation with long chain polyunsaturated omega 3 and omega 6 fatty acids, 10 received 3 months of placebo (sunflower oil). Venous blood was sampled at 0 and 12 weeks; whole blood WBC aggregation in response to formyl-methionyl-leucyl-phenylalanine (FMLP) was measured. The results showed that the 3 months' dietary supplementation with a combination of omega 3 and omega 6 fatty acids significantly reduced WBC aggregation to FMLP in healthy volunteers when compared to placebo. Since WBC aggregation to FMLP is dependent on the activity of WBC surface receptors and independent of eicosanoid production, we suggest EFAs may have other anti-inflammatory actions in addition to their role as modulators of mediator production.

The risk of treatment. A study of rheumatoid arthritis patients' attitudes

Despite its importance, there is no well-validated method of measuring patients' concept of 'acceptable' risk of medical treatment. Numerical methods give widely varying results depending on the methodology. We have attempted to assess 'acceptable' risk using relative comparisons. We administered a questionnaire to 67 patients with rheumatoid arthritis (RA). In general, patients' estimate of acceptable risk was less than the actual risk of treatment. Some illogical choices were made, showing poor understanding by patients of the concepts of risk and risk:benefit ratio. Patients appeared willing to accept higher levels of risk from procedures than from drug treatment. Willingness to accept risk in exchange for successful treatment of their RA did not correlate with disease severity, age, willingness to take non-medical risks or family responsibilities.

Confirmation of the beneficial effects of brief coincubation of gametes in human in vitro fertilization

OBJECTIVE

To confirm whether brief exposure of human oocytes to spermatozoa in vitro results in equivalent fertilization rates and possibly better quality embryos than overnight coincubation and to determine if there was a difference in outcome with regard to the type of culture medium used.

DESIGN

Prospective distribution of gametes between treatments in sequential patients.

SETTING

Assisted reproductive technology program in private hospital.

PATIENT(S)

Consecutively treated subfertile couples entering an infertility program.

INTERVENTION(S)

Assisted reproductive technology treatment for infertility involving oocyte retrieval and in vitro fertilization.

MAIN OUTCOME MEASURE(S)

When possible, the outcome of fertilization and embryo quality were compared when gametes were coincubated for 1 hour or overnight. Two different formulations of human tubal fluid were compared in some cases.

RESULT(S)

There was no statistically significant difference in fertilization rates between a brief or overnight coincubation of gametes or between the two treatment groups with regard to the type of culture medium used. The quality of the embryos was significantly better in the 1-hour exposure group. The embryos in Basal XI human tubal fluid medium were of significantly better morphological quality than their siblings in D3+ human tubal fluid medium.

CONCLUSION(S)

Coincubation of oocytes and spermatozoa for a shorter period produced embryos of superior morphological quality than the generally accepted overnight protocol. A simple glucose and phosphate-free human tubal fluid medium resulted in early cleavage embryos of better morphological quality than a medium supplemented with glucose, taurine, and glutathione.

Hepatitis A virus infections in urban children--are preventive opportunities being missed?

To determine the prevalence of hepatitis A virus (HAV) infections in children in a large urban center, a point prevalence survey was conducted using a novel, ultrasensitive assay for HAV-specific IgG in saliva. A structured sample of 224 grade-six students (5.8% of grade registrants) was obtained from 23 schools throughout Vancouver. All students provided saliva samples adequate for testing. The anti-HAV prevalence rate was 7.1% (95% confidence interval, 4.1%-11.3%). Among 167 Canadian-born students, only 5 (3%) were positive, whereas among 57 students born elsewhere, 11 (19.3%) were positive (P < .001), with circumstances in the latter group supporting infection prior to emigration. No clustering of positive persons was evident. The cumulative risk of HAV infection in Canadian-born children was low through age 11-12 years even in less affluent parts of the city, speaking against a need for routine use of HAV vaccine in this setting.

Posttransplant lymphoproliferative disease in primary Epstein-Barr virus infection after liver transplantation: the role of cytomegalovirus disease

Epstein-Barr virus (EBV) plays a major role in the pathogenesis of posttransplant lymphoproliferative disease (PTLD). Patients who undergo primary EBV infection after transplantation are at greater risk of developing PTLD. In this retrospective study, the incidence of EBV infection and associated PTLD in 40 consecutive adult recipients who were seronegative for EBV at the time of liver transplantation were investigated, and risk factors for PTLD were analyzed. Of 37 patients with available timely posttransplant serum samples, 35 (95%) developed primary EBV infection. Of the 40 patients, 13 (33%) developed PTLD a median of 126 days (range, 48-776) after liver transplantation. The factor significantly associated with the development of PTLD was cytomegalovirus disease (relative risk, 7.3; 95% confidence interval, 2.36-22.6; P = .0006). Cytomegalovirus disease is a predictor for the development of PTLD in primary EBV infection after liver transplantation, and it may be a target for prophylactic intervention.

Specificity and functional activity of anti-Burkholderia pseudomallei polysaccharide antibodies

The lipopolysaccharide (LPS) of Burkholderia pseudomallei, the causative agent of melioidosis, consists of two O-antigenic polysaccharides designated O-PS I and O-PS II. In this study, the O-PS specificity and functional activity of a protective polyclonal antiserum and an immunoglobulin M (IgM) monoclonal antibody were determined. The polyclonal antiserum recognized both O-PS I and O-PS II, while the monoclonal antibody was O-PS II specific. Both mediated phagocytic killing of B. pseudomallei by polymorphonuclear leukocytes. Patients acutely infected with B. pseudomallei also produced antibodies to the two O-PSs, but these antibodies were not produced by asymptomatic individuals from an area of endemicity who were seropositive by an indirect hemagglutination test using sonicated heat-killed whole organisms as antigen. IgM antibodies were detected only in patients with localized infection. IgG antibodies were detected in all acutely infected patients, but there was no significant difference in antibody levels among patients with localized infection, patients who survived septicemic illness, and patients who died from septicemic illness. Further analysis of the IgG response revealed production of IgG1 and IgG2 antibodies by all patient groups, while an IgG3 response was seen only in survivors of septicemic infection. IgG4 was not detectable even when a fivefold-lower serum dilution was used. Patient sera also mediated phagocytic killing by polymorphonuclear leukocytes, and the killing effect was enhanced by complement. These results suggest that antibodies to the LPS O-polysaccharides of B. pseudomallei are protective by promoting phagocytic killing. The antibodies develop during human infection and may facilitate clearance of the organisms, as seen in a diabetic rat model of B. pseudomallei infection.

Differences in bimanual coordination associated with stuttering

The motor coordination of adults who stutter was examined in the performance of a bimanual movement task. Fifteen subjects who stutter and 15 matched subjects who do not stutter performed three trials of a bimanual finger movement task. Subjects were required to produce a flexion and extension movement of the metacarpophalangeal joint of each index finger in rhythm to a metronome. The rate of movement increased during the 70 s trial. Stutterers could maintain movements at the prescribed rate as well as nonstutterers; however, stutterers moved with less amplitude and peak velocity. In addition, dynamical analysis revealed that subjects who stutter exhibited greater relative phase variability than subjects who do not stutter. These results shed new light on the mixed results of earlier studies on nonspeech motor performance of individuals who stutter and suggest that there are strategic differences as well as coordination differences that should be observable across a variety on motor tasks requiring coordination of multiple effectors.

Characterization of the capsular polysaccharide of Burkholderia (Pseudomonas) pseudomallei 304b

Burkholderia (Pseudomonas) pseudomallei is the causative agent of melioidosis, a bacterial infection of considerable morbidity in areas of endemicity of Southeast Asia and northern Australia. Clinical isolates of B. pseudomallei have been demonstrated to produce a lipopolysaccharide (LPS) containing two separate and chemically distinct antigenic O polysaccharides against which infected patients produced antibodies. A putative capsular polysaccharide (CPS) has also been reported and is thought to be antigenically conserved based on results of serological studies with clinical B. pseudomallei isolates. In the present study, the CPS isolated from B. pseudomallei 304b from northeastern Thailand was found to have an [alpha]D of +99 degrees (water), was composed of D-galactose (D-Gal), 3-deoxy-D-manno-2-octulosonic acid (KDO), and O-acetyl 3:1:1), and was a linear unbranched polymer of repeating tetrasaccharide units having the following structure: -3)-2-O-Ac-beta-D-Galp-(1-4)-alpha-D-Galp-(1-3)-beta-D -Galp-(1-5)-beta-D-KDOp-(2-. Sera from 13 of 15 patients with different clinical manifestations of melioidosis but not normal controls recognize the CPS, which suggests that it is immunogenic and raises the possibility that it may have a role as a vaccine candidate and/or diagnostic agent.

The effect of calcium supplementation on bone density during lactation and after weaning

BACKGROUND

Women may lose bone during lactation because of calcium lost in breast milk. We studied whether calcium supplementation prevents bone loss during lactation or augments bone gain after weaning.

METHODS

We conducted two randomized, placebo-controlled trials of calcium supplementation (1 g per day) in postpartum women. In one trial (the study of lactation), 97 lactating and 99 nonlactating women were enrolled a mean (+/-SD) of 16+/-2 days post partum. In the second trial (the study of weaning), 95 lactating women who weaned their infants in the 2 months after enrollment and 92 nonlactating women were enrolled 5.6+/-0.8 months post partum. The bone density of the total body, lumbar spine, and forearm was measured at enrollment and after three and six months.

RESULTS

The bone density of the lumbar spine decreased by 4.2 percent in the lactating women receiving calcium and by 4.9 percent in those receiving placebo and increased by 2.2 and 0.4 percent, respectively, in the nonlactating women (P<0.001 for the effect of lactation; P= 0.01 for the effect of calcium). After weaning, the bone density of the lumbar spine increased by 5.9 percent in the lactating women receiving calcium and by 4.4 percent in those receiving placebo; it increased by 2.5 and 1.6 percent, respectively, in the nonlactating women (P<0.001 for the effects of lactation and calcium). There was no effect of either lactation or calcium supplementation on bone density in the forearm, and there was no effect of calcium supplementation on the calcium concentration in breast milk.

CONCLUSIONS

Calcium supplementation does not prevent bone loss during lactation and only slightly enhances the gain in bone density after weaning.

Microvascular abnormalities in patients with vibration white finger

In vivo nailfold capillary microscopy was performed on 10 men with vibration white finger (VWF) and 10 age-matched male controls. The observed nailfold capillaries required adaptation of Maricq's classifications and addition of new morphological scoring systems. These new classifications produced numerical scores for assessing capillary: dropout, tortuosity, elongation, visualization of subpapillary venular plexus, and the degree of disarrangement of nailfold capillary polarity. Application of these new scores showed, for the first time, a complex pattern of abnormal-nailfold capillaries in patients with VWF. Capillary dropout was evident in 7/10 patients, with an associated disarrangement in nailfold capillary polarity in five. All 10 controls had normal capillary morphology. Tortuosity of the capillary loops and elongation of their length was observed in 30% of patients. These significant morphological alterations seen in VWF suggest a local small-vessel vasculitis.

Factors affecting the pharmacokinetics of parenteral chloramphenicol in enteric fever

Chloramphenicol pharmacokinetics were studied in 29 Nepalese adults diagnosed with uncomplicated enteric fever and randomized to receive succinate ester 30 mg/kg i.v. or i.m. Serial plasma concentrations of chloramphenicol, and iothalamate (to estimate glomerular filtration rate), antipyrine (hepatocellular function) and Indocyanine Green (liver blood flow) were measured by HPLC and kinetic parameters estimated by non-compartmental analysis. In culture-positive patients (n = 16), mean residence times (MRTs) and steady-state volumes of distribution (V(d)ss) for i.v. chloramphenicol (mean +/- S.D.; 4.9 +/- 0.9 h and 1.9 +/- 0.8 L/kg; n = 7) were less than after i.m. chloramphenicol (12.3 +/- 7.3 h and 3.7 +/- 2.5 L/kg; n = 9; P < 0.05), with a higher peak plasma concentration after i.v. (16.2 +/- 9.1 versus 7.8 +/- 3.6 mg/L; P < 0.05); plasma clearance (Cl(p)) was similar in the two groups (368 +/- 172 and 310 +/- 224 mL/kg/min after i.v. and i.m. respectively). In 17 patients examined during convalescence, MRT and Vdss were less than in acute illness regardless of route chloramphenicol administration. There were similar changes in chloramphenicol kinetic parameters in culture-negative patients. Antipyrine Cl(p) and liver blood flow correlated weakly with chloramphenicol Cl(p) in culture-positive patients (P < 0.1) and were higher in convalescence; no such associations were seen for iothalamate Cl(p). These data indicate that i.v. chloramphenicol produces peak plasma concentrations which are on average twice those after i.m. injection of the same dose, due principally to a smaller V(d)ss. Cl(p) is uninfluenced by route of administration and is determined more by hepatic metabolism than renal excretion. Intramuscular treatment may result in sub-therapeutic chloramphenicol concentrations initially, but continued regular i.v. dosing is more likely to produce levels at which bone marrow toxicity occurs.

(+)-WAY 100135, a partial agonist, at native and recombinant 5-HT1B/1D receptors

1. We have studied the effects of the purportedly selective 5-HT1A receptor antagonist (+)-WAY 100135 on electrically stimulated 5-hydroxytryptamine (5-HT) efflux in the ventrolateral geniculate nucleus (vLGN), and its affinity at human 5-HT1B and 5-HT1D receptors stably expressed in Chinese hamster ovary (CHO) cells. 2. On short 'pseudo single pulse' stimulations (20 pulses at 100 Hz, 190 ms train duration), (+)-WAY 100135 (1.0 microM) decreased 5-HT efflux in the vLGN to 68 +/- 8% of pre-drug values (P < 0.01). This decrease could be blocked by the 5-HT1D/1B receptor antagonist GR 127935 (50 nM). Conversely, when long stimulations (20 pulses at 20 Hz, 950 ms train) were used, (+)-WAY 100135 had no effect on 5-HT efflux (84 +/- 8% of pre-drug values) although both methiothepin (200 nM) and GR 127935 (50 nM) caused significant increases (to 175 +/- 18 and 130 +/- 10% of pre-drug values, respectively). 3. Paroxetine (100 nM), the selective 5-HT reuptake inhibitor, increased stimulated 5-HT efflux and reuptake half-life (to 145 +/- 18% and 649 +/- 121%, respectively) on pseudo single pulse stimulations. When (+)-WAY 100135 was added in combination with the uptake blocker, the effect of paroxetine on stimulated 5-HT efflux was potentiated to 282 +/- 48% (P < 0.01) without further effect on the 5-HT reuptake half-life. 4. The affinity and intrinsic activity of (+)-WAY 100135 were determined at recombinant human 5-HT1B and 5-HT1D receptors expressed in CHO cells, by use of radioligand binding and [35S]-GTP gamma S binding (+)-WAY 100135 was a partial agonist at human 5-HT1B and 5-HT1D receptors with moderately high affinity for 5-HT1D receptors (pEC50 = 7.61). 5. In conclusion, (+)-WAY 100135 was found to be not a selective 5-HT1A autoreceptor antagonist but may act as a partial agonist at the 5-HT1B/1D receptor, displaying agonist or antagonist properties depending on the stimulation protocol used and the resultant 5-HT 'tone' at the receptor.

Randomized trial of varying mineral intake on total body bone mineral accretion during the first year of life

OBJECTIVE

The effect of varying mineral intakes on total body bone mass accretion during the first year of life in healthy full-term infants is unknown. The purpose of this study was to determine whether total body bone mass accretion during the first year of life was influenced by the calcium and phosphorus intake of an infant and whether early differences in bone accretion persist through 1 year of age.

DESIGN

This prospective, randomized trial was conducted in two phases. In phase I, 67 infants were randomized within the first 2 weeks of life into either a low (439 mg of calcium per liter and 240 mg of phosphorus per liter) or moderate (510 mg of calcium per liter and 390 mg of phosphorus per liter) mineral-containing formula feeding group. An additional group of 34 human milk-fed (low mineral) infants also was enrolled. Phase II involved an additional randomization of all infants at 6 months of age into moderate-mineral formula (see above), high-mineral formula (1350 mg of calcium per liter and 900 mg of phosphorus per liter), or cow milk (1230 mg of calcium per liter and 960 mg of phosphorus per liter) feeding group. Anthropometric measurements, nutrient intake, and total body bone mineral content (BMC) by dual-energy x-ray absorptiometry were measured at 1, 3, 6, 9, and 12 months.

RESULTS

During the first 6 months, the moderate-mineral group had a greater increase in weight (3.42 +/- 0.62 kg) compared with the human milk group (2.93 +/- 0.56 kg); the low-mineral group (3.19 +/- 0.62 kg) was intermediate. Bone mass accretion differed in a similar direction, with the moderate-mineral feeding group having a greater increase than the human milk group and the low-mineral group being intermediate of the two. Including weight, length, and bone area as covariates, both the low-mineral formula- and human milk-fed groups had similar BMC, which was lower than that of the moderate-mineral group at 3 and 6 months of age. Adjusted mean BMC values for the moderate-mineral formula-fed group compared with the low-mineral formula- and human milk-fed groups were 127.8 +/- 1.5 (SEM) g vs 119. 2 +/- 1.5 and 122.1 +/- 1.4 g, respectively, at 3 months of age and 168.7 +/- 2.5 g vs 157.6 +/- 2.5 and 158.7 +/- 2.4 g, respectively, at 6 months of age. The BMC at 6 months of age among the formula-fed infants was correlated with both average dietary phosphorus intake (r = .592) and average daily calcium intake (r = .620) during the first 6 months. The relationships between BMC and these minerals remained significant even after controlling for caloric intake. It was not possible to determine the independent effects of dietary calcium and phosphorus on BMC because of the strong correlation of these minerals with each other. Despite significant differences in both calcium and phosphorus intakes during the second 6 months of life, there were no differences in growth parameters or bone mass accretion. Means for BMC, adjusted for body weight, length, and bone area, were not significantly different among feeding groups at either 9 or 12 months of age. Adjusted means were 199 +/- 2 (SEM) and 237 +/- 3 g at 9 and 12 months of age for infants receiving moderate-mineral formula; 198 +/- 2 and 236 +/- 3 g at 9 and 12 months of age for infants receiving the high-mineral formulas and 202 +/- 5 and 233 +/- 5 g at 9 and 12 months of age for infants receiving cow milk. The gain in bone mass during the second 6 months differed by the first 6-month feeding group; mean changes in BMC between 6 and 12 months, adjusted for changes in weight, length, and bone area, were greater in human milk-fed infants than in either the low- or moderate-mineral-containing formula groups: 81 +/- 16 g in human milk-fed infants and 73 +/- 15 and 71 +/- 15 g in the low- and moderate-mineral formula groups, respectively. Infants fed whole cow milk during the second 6 months were excluded from this analysis because of the small number of infants completing the study. By 12 months of age t

Promiscuity of clinical Plasmodium falciparum isolates for multiple adhesion molecules under flow conditions

The central pathologic process in severe Plasmodium falciparum malaria is the cytoadherence of parasitized erythrocytes to capillary and postcapillary venular endothelium, with resultant tissue hypoxia, metabolic disturbances, and multiorgan dysfunction. The molecular basis of this process has been studied extensively using static adhesion assays. In the present study, we determined whether infected red blood cells (IRBC) from clinical parasite isolates would roll and adhere on CD36, ICAM-1, E-selectin, P-selectin, and VCAM-1 using a laminar flow system that allowed for the direct visualization of IRBC-substratum interactions. The results indicate that IRBC could tether and roll on CD36, ICAM-1, P-selectin, and VCAM-1 in a shear-dependent fashion, but significant adhesion was restricted to CD36. There was no interaction with E-selectin. When both CD36 and ICAM-1 were expressed on the same cellular substratum such as C32 melanoma cells, adhesion was significantly greater than when CD36 was present alone. The adhesive interactions were different from those between leukocytes and the same adhesion molecules. Furthermore, IRBC rolling on P-selectin and VCAM-1 was not inhibitable by Abs that entirely prevented leukocyte-receptor interactions. These findings suggest that cytoadherence under physiologic conditions may be a multistep process similar to that involved in the recruitment of a number of different cell types. Further elucidation of the molecular basis of these novel interactions is crucial for the development of therapeutic interventions aimed at inhibiting or reversing the process.

Promiscuity of clinical Plasmodium falciparum isolates for multiple adhesion molecules under flow conditions

The central pathologic process in severe Plasmodium falciparum malaria is the cytoadherence of parasitized erythrocytes to capillary and postcapillary venular endothelium, with resultant tissue hypoxia, metabolic disturbances, and multiorgan dysfunction. The molecular basis of this process has been studied extensively using static adhesion assays. In the present study, we determined whether infected red blood cells (IRBC) from clinical parasite isolates would roll and adhere on CD36, ICAM-1, E-selectin, P-selectin, and VCAM-1 using a laminar flow system that allowed for the direct visualization of IRBC-substratum interactions. The results indicate that IRBC could tether and roll on CD36, ICAM-1, P-selectin, and VCAM-1 in a shear-dependent fashion, but significant adhesion was restricted to CD36. There was no interaction with E-selectin. When both CD36 and ICAM-1 were expressed on the same cellular substratum such as C32 melanoma cells, adhesion was significantly greater than when CD36 was present alone. The adhesive interactions were different from those between leukocytes and the same adhesion molecules. Furthermore, IRBC rolling on P-selectin and VCAM-1 was not inhibitable by Abs that entirely prevented leukocyte-receptor interactions. These findings suggest that cytoadherence under physiologic conditions may be a multistep process similar to that involved in the recruitment of a number of different cell types. Further elucidation of the molecular basis of these novel interactions is crucial for the development of therapeutic interventions aimed at inhibiting or reversing the process.

Is the quality of diabetes care better in a diabetes clinic or in a general medicine clinic?

OBJECTIVE

To compare the quality of ambulatory diabetes care delivered by physicians in the diabetes clinic versus the general medicine clinic of a university-affiliated Veterans Administration medical center.

RESEARCH DESIGN AND METHODS

This is a retrospective study that involved the review of medical records against predetermined process-of-care criteria. A total of 112 patients with diabetes were randomly selected, of whom 56 were cared for in the general medicine clinic and 56 in the diabetes clinic. The following main outcome measures were examined: 1) the compliance with individual criteria; and 2) the proportion of patient visits in each clinic receiving minimally acceptable quality, defined as a blood pressure measurement, a record of type of hypoglycemic medication, a glycated hemoglobin measurement within the past year, a urinalysis within the past year, an ophthalmologist or optometrist eye examination within the past year or scheduled in the next six months, a record of change in therapeutic management, and a scheduled return visit.

RESULTS

The diabetes clinic performed significantly better than the general medicine clinic on the following criteria: a record of a patient's self-monitoring of blood glucose levels; a foot examination; a comprehensive eye examination; a glycated hemoglobin measurement; and a referral for diabetic education. The proportion of patient visits meeting the minimally acceptable levels of quality was better in the diabetes clinic than the general medicine clinic (73 vs. 52%, P = 0.02).

CONCLUSIONS

Patients cared for by physicians in the diabetes clinic receive better quality of diabetes care than do patients cared for by physicians in the general medical clinic. If patient care is to be shifted from specialists to generalists, additional attention needs to be paid to ensure that generalists have the knowledge and system resources necessary to deliver an acceptable quality of diabetes care.

Fatty acid composition of adipose tissue, an indication of dietary fatty acids, and breast cancer prognosis

PURPOSE

Fatty acid composition of adipose tissue is an indicator of the long-term ingestion pattern of several specific fatty acids. There is good correlation of antecedent diet with the essential fatty acids, and there is reflection of the diet with the fatty acids that can be synthesized. The relationship between the fatty acid levels and lymph node status and clinical outcome was examined.

METHODS

At the time of diagnostic surgery, 161 women with clinical stage T1NO breast cancer had subcutaneous adipose tissue (breast and abdominal) aspirated. The concentrations of 35 fatty acids, seven summed classes, and six fatty acid groups were measured by capillary gas chromatography. Lymph node status was determined with axillary dissection, and patients were followed-up (mean, 7.3 years) for clinical outcome.

RESULTS

There was no significant association of any adipose tissue fatty acids with overall survival, although few (16 of 161 women) died of breast cancer. However, the odds of having positive lymph nodes (57 of 161 women) were significantly higher for women with a greater adipose tissue proportion of oleic acid (odds ratio [OR], 7.56; 95% confidence interval [CI], 1.78 to 32.1) or total saturated acids (OR, 8.43; 95% CI, 1.48 to 40.0) and significantly lower with a higher proportion of trans fatty acids (OR, 0.24; 95% CI, 0.07 to 0.77), as assessed by multivariate logistic regression.

CONCLUSION

These data support previous research with dietary questionnaire methodology, suggesting that specific dietary fatty acids may be associated with breast cancer promotion. Further research with long-term clinical follow-up is necessary to investigate these observations in large, diverse populations before dietary recommendations can be envisioned.

Increased gastrointestinal permeability in patients with Plasmodium falciparum malaria

Sequential gastrointestinal permeability in patients with Plasmodium falciparum malaria was determined by measuring the permeation of sucrose, lactulose, and mannitol to assess both gastric and small intestine permeability. Sucrose absorption (gastroduodenal permeability) was increased in patients with severe malaria (defined as either >5% parasitemia or a serum bilirubin level of >50 micromol/L) and became normal by day 2 following treatment. A similar proportion of patients with uncomplicated malaria had increased gastroduodenal permeability initially, which resolved by day 7 of treatment. During acute malarial illness, the lactulose: mannitol (L:M) ratio in urine was increased and was found to be higher in patients with severe malaria than in those with uncomplicated malaria and in controls, but this ratio reverted to normal during convalescence. At the time of admission, the L:M ratios in patients with uncomplicated malaria were increased but became normal by day 2 after treatment. Conversely, the duration of increased L:M ratios in patients with severe malaria was longer. By day 7, the L:M ratios in patients with severe malaria were higher than those in patients with uncomplicated malaria and in controls. We conclude that gastrointestinal permeability is increased during severe and uncomplicated falciparum malaria but reverts to normal during convalescence.

Opisthorchis viverrini infection in Thailand: studies on the morbidity of the infection and resolution following praziquantel treatment

A community study on opisthorchiasis was conducted in Prachinburi Province in eastern Thailand during 1990-1992. The morbidity from opisthorchiasis in the community and reversibility of biliary pathology following treatment with praziquantel at a single dose of 40 mg/kg were assessed by longitudinal investigations of clinical, laboratory, and ultrasonographic changes. A total of 913 voluntary subjects infected with Opisthorchis viverrini were randomly selected for longitudinal study, and 579 subjects without liver fluke infection were recruited as controls. The majority of the study group suffered from mild and moderate infections that were associated with nonspecific gastrointestinal symptoms. Grade I and II ultrasonographic changes, which indicated chronic inflammation of the biliary tract and gallbladder, were detected in 32% of the infected individuals. Clinical symptoms and ultrasonographic changes were common in subjects 21-40 years of age and older. Satisfactory resolution of morbidity was observed during two years follow-up on days 0, 60, 180, 360, and 720, as shown by significant clinical improvement, normalization of laboratory parameters, and downgrading of ultrasonographic abnormalities. Portable ultrasonography has proved to be a reliable noninvasive technique in the evaluation of the morbidity due to opisthorchiasis in rural areas.

Radiosurgery for brain metastases: relationship of dose and pattern of enhancement to local control

PURPOSE

This study aimed to analyze dose, initial pattern of enhancement, and other factors associated with freedom from progression (FFP) of brain metastases after radiosurgery (RS).

METHODS AND MATERIALS

All brain metastases treated with gamma-knife RS at the University of California, San Francisco, from 1991 to 1994 were reviewed. Evaluable lesions were those with follow-up magnetic resonance or computed tomographic imaging. Actuarial FFP was calculated using the Kaplan-Meier method, measuring FFP from the date of RS to the first imaging study showing tumor progression. Controlled lesions were censored at the time of the last imaging study. Multivariate analyses were performed using a stepwise Cox proportional hazards model.

RESULTS

Of 261 lesions treated in 119 patients, 219 lesions in 100 patients were evaluable. Major histologies included adenocarcinoma (86 lesions), melanoma (77), renal cell carcinoma (21), and carcinoma not otherwise specified (17). The median prescribed RS dose was 18.5 Gy (range, 10-22) and the median tumor volume was 1.3 ml (range, 0.02-30.9). The initial pattern of contrast enhancement was homogeneous in 68% of lesions, heterogeneous in 12%, and ring-enhancing in 19%. The actuarial FFP was 82% at 6 months and 77% at 1 year for all lesions, and 93 and 90%, respectively, for 145 lesions receiving > or = 18 Gy. Multivariate analysis showed that longer FFP was significantly associated with higher prescribed RS dose, a homogeneous pattern of contrast enhancement, and a longer interval between primary diagnosis and RS. Adjusted for these factors, adenocarcinomas had longer FFP than melanomas. No significant differences in FFP were noted among lesions undergoing RS for recurrence after prior radiotherapy (119 lesions), RS alone as initial treatment (45), or RS boost (55).

CONCLUSION

A minimum prescribed radiosurgical dose > or = 18 Gy yields excellent local control of brain metastases. The influence of pattern of enhancement on local control, a new finding in this retrospective analysis, needs to be confirmed.

Pasteurella multocida toxin activates the inositol triphosphate signaling pathway in Xenopus oocytes via G(q)alpha-coupled phospholipase C-beta1

Pasteurella multocida toxin (PMT) has been hypothesized to cause activation of a GTP-binding protein (G-protein)-coupled phosphatidylinositol-specific phospholipase C (PLC) in intact cells. We used voltage-clamped Xenopus oocytes to test for direct PMT-mediated stimulation of PLC by monitoring the endogenous Ca2+-dependent C1- current. Injection of PMT induced an inward, two-component Cl- current, similar to that evoked by injection of IP3 through intracellular Ca2+ mobilization and Ca2+ influx through voltage-gated Ca2+ channels. These PMT-induced currents were blocked by specific inhibitors of Ca2+ and Cl- channels, removal of extracellular Ca2+, or chelation of intracellular Ca2+. Specific antibodies directed against an N-terminal, but not a C-terminal, peptide of PMT inhibited the toxin-induced currents, implicating that the N terminus of PMT is important for toxin activity. Injection with specific antibodies against PLCbeta1, PLCbeta2, PLCbeta3, or PLCgamma1 identified PLCbeta1 as the primary mediator of the PMT-induced Cl- currents. Injection with guanosine 5'-O-(2-(thio)diphosphate), antibodies to the common GTP-binding region of G-protein alpha subunits, or antibodies to different regions of G-protein beta subunits established the involvement of a G-protein alpha subunit in PMT-activation of PLCbeta1. Injection with specific antibodies against the alpha-subunits of G(q/11), G(s/olf), G(i/o/t/z), or G(i-1/i-2/i-3) isoforms confirmed the involvement of Gq/11alpha. Preinjection of oocytes with pertussis toxin enhanced the PMT response. Overexpression of G(q)alpha in oocytes could enhance the PMT response by 30-fold to more than 300-fold, whereas introduction of antisense G(q)alpha cRNA reduced the response by 7-fold. The effects of various specific antibodies on the PMT response were reproduced in oocytes overexpressing G(q)alpha.

New, ultrasensitive enzyme immunoassay for detecting vaccine- and disease-induced hepatitis A virus-specific immunoglobulin G in saliva

Although detection of disease-induced hepatitis A virus (HAV)-specific antibodies in saliva has been successfully utilized in a few epidemiological studies, available assays fail to detect lower salivary anti-HAV levels associated with vaccine-induced immunity. We present a new capture enzyme immunoassay which employs a three-layer antibody recognition system. Evaluation of paired saliva-serum specimens from 1,025 international travellers, 134 other volunteers, and 91 hepatitis A vaccine recipients demonstrated 99.6% (95% confidence interval, 98.4 to 99.9) specificity and 98.7% (95% confidence interval, 97.7 to 99.4) sensitivity of this salivary assay in differentiating between immune and susceptible individuals, compared with serum-based methods. We conclude that this assay is sufficiently sensitive for reliable detection of both vaccine- and infection-induced HAV-specific immunoglobulin G in saliva, even when corresponding anti-HAV levels in serum are very low (< 1 IU/ml).